Bit of a simple question, but on Alex’s road bike with Shimano 5700 brakes, there is not much clearance with a Continental 28c tyre (actually 26.5-27 measured). It’s the underside of the caliper that seems to be the pinch point rather than the brake bridge itself.
If I wanted to go BIIIIG (say 30c tyre), would changing to a Dia Comp/Paul Centerpull brake provide any more tyre clearance??
The “h’s” are back!
It seems fork clearance would be the issue.
Yeah good point… goes and checks.
Actually the carbon fork clearance is really good, it’s mostly the brake caliper itself.
Yeah nah. The centrepull brake is still going to be attached at the brake bridge, so double check that the clearance is actually any better.
BUT FIRST: think about it. You’re going from a standard (short) reach caliper that’s probs doesn’t have the pads maxed out at the bottom of the slots. Are longer reach arms going to put the pads lower than the braking surface even at the top of the slots?
If the bridge itself isn’t the problem, maybe looking around for a caliper that has less material in that area might be a better option.
Edit: I run short-reach Sora dual-pivots on my commuter, and the brake bridge is lower than the caliper itself. ie, when I go to bigger than 29mm actual the tyre hits the bridge first, not the brake.
When i had my sorenson, i couldn’t put 25c GP4000’s on because they would rub on the underside of the Sram force calipers. That is, until enough material wore away and they spun freeeeeeeeeeeeeeeee
There are short reach centrepulls:
And the arms do move away from the tyre under braking.
But you then have to put hangers somewhere too.
Single pivots often have better clearance, older campy (80s) brakes can be spectacular in this regard.
Thanks guys. The hanger isnt is a huge problem is it- you can use a seatpost adaptor thing
try a few different sets of callipers first?
My 90’s road Ken won’t take 30mm CX tyres with campy dual pivots, but will with older dual pivot shitmano 600’s.
you can also adjust the balance or centering screw (i think thats what it is) on dual pivots to move the actual brake arms (with the pads on the ends) relative to the mounting bolt without affecting pad clearance. You’ll then have to center up the brake using the brake bolt, this can help work if the stationary bit of the brake with the brake bolt attached has clearance but that arms themselves are the problem.
I did this on my commuter where the brake arms were resting on the fenders and managed to juggle everything to get ~3mm more clearance.
I think i’ve got a few pairs of fairly spindly looking (probs max vertical clearance) single pivots at home that you can have if they suit your purpose.
I had the brake bridge moved up 5mmm on one of my frames, to give clearance for bigger tyres. Was getting the frame repainted anyway so…